Modification of the cellular gene expression program through regulation of transcription is a key mechanism for control of normal development and a causal agent of disease in multi-cellular organisms. Recently, chromatin remodeling has emerged as an important regulator of transcriptional activation and repression. Chromatin remodeling complexes alter the accessibility of the DNA to transcription factors or to the transcriptional machinery by inducing non-covalent, local changes in the DNA-nucleosome association. While the mechanics of chromatin remodeling are being elucidated, the role of chromatin remodeling in multicellular eukaryote development is less well understood. We are well positioned to address this question because we have recently isolated a viable mutant in a chromatin remodeling ATPase homolog called SPLAYED (SYD). Mutations in SYD cause distinct developmental defects in the plant model system Arabidopsis thaliana. To investigate the developmental role of chromatin remodeling we seek: 1) to demonstrate that SYD is a component of a complex that exhibits chromatin remodeling activity, using doubly epitope tagged, biologically active SYD protein and SYD-specific antibodies we generated; 2) to define the precise role of SYD in stem cell maintenance, an important developmental pathway of which SYD is a component, using a combined genetic and molecular approach; and 3) taking advantage of the unique strength of our system, to genetically identify and characterize factors that act together with or antagonistically to SYD in developmental control. Through defining the molecular mechanism of action of SYD and the role of SYD and SYD-interacting factors in Arabidopsis development, we hope to contribute to the understanding of the role of chromatin remodeling in multicellular eukaryote development. [unreadable] [unreadable] [unreadable]